Question

#14 Thin Soap Films: Maximizing Reflection A soap bubble consists of a film with an index of refraction of 1.50, with air on either side of the film. What is the minimum thickness of the film such that red light with a wavelength of 700 nm is reflected with the greatest intensity? O A. 117 nm B. 233 nm O C. 350 nm O D. 700 nm #15 Thin Soap Films: Maximizing Reflection A soap bubble consists of a film with an index of refraction of 1.5, with air on either side of the film. What is the minimum thickness of the film such that red light with a wavelength of 700 nm is reflected with the greatest intensity? A. 117 nm B. 233 nm O C. 350 nm O D. 700 nm #16 Thin Films: Minimizing Glare A thin film with an index of refraction of 1.35 is applied to an automobile windshield (with air above the film), for which the index of refraction is 1.50. What is the minimum thickness of the film such that reflection of 500 nm light is minimized? O A. 92.6 nm B. 125 nm C. 185 nm O D. 250 nm #17 Mean and Green: Maximizing Reflection Suppose in #16 as an intimidation tactic, one wishes to maximize the reflection of green light from one's automobile windshield. What is the minimum thickness needed to accomplish this aim? O A. 92.6 nm B. 125 nm O C. 185 nm O D. 250 nm OOO0 O000

Answer 1

#14 Thin Soap Films : Maximizing Reflection

What is the minimum thickness of a film such that red light is reflected with the greatest intensity?

To minimize reflection, we want destructive interference.

2 n t = [m + (1/2) $\lambda$

where, n = refractive index of a thin soap film = 1.50

$\lambda$ = wavelength of red light = 700 x 10^-9 m

m = fringe order = 0

then, we get

t = (700 x 10^-9 m) / [(4) (1.50)]

t = [(700 x 10^-9 m) / (6)]

t = 1.17 x 10^-7 m

converting m into nm :

t = 117 nm

Option (A) : it will be correct.

#15 Thin Soap Films : Maximizing Reflection

What is the minimum thickness of a film such that red light is reflected with the greatest intensity?

To minimize reflection, we want destructive interference.

2 n t = [m + (1/2) $\lambda$

where, n = refractive index of a thin soap film = 1.50

$\lambda$ = wavelength of red light = 700 x 10^-9 m

m = fringe order = 0

then, we get

t = (700 x 10^-9 m) / [(4) (1.50)]

t = [(700 x 10^-9 m) / (6)]

t = 1.17 x 10^-7 m

converting m into nm :

t = 117 nm

Option (A) : it will be correct.

#16 Thin Films : Minimizing Glare

What is the minimum thickness of a film such that reflection of light is minimized?

To minimize reflection, we want destructive interference.

2 n t = [m + (1/2) $\lambda$

where, n = refractive index of a thin film = 1.35

$\lambda$ = wavelength of reflection light = 500 x 10^-9 m

m = fringe order = 0

then, we get

t = (500 x 10^-9 m) / [(4) (1.35)]

t = [(500 x 10^-9 m) / (5.40)]

t = 9.26 x 10^-8 m

converting m into nm :

t = 92.6 nm

Option (A) : it will be correct.